Improvement in combined burglar-alarms and door-fasteners



W.'S. WATKINS.

Combined Burglar Alarm and Door-Fastener. No; 168,200, Patnted Sept. 23,1815;

N PEIERS, PHOTO LITHDGRAPHER, WASHINGTON. D. C

UNITED STATES PATENT Orrron.

WILLIAM s. WATKINS, on ST. LOUIS, MISSOURI.

IMPROVEMENT IN COMBINED BURGLAR-ALARMS AND DOOR-FASTENERS.

Specification forming part of Letters Patent No. 168,200, dated September 28, 1875; application filed September 20, 1875,

St. Louis, in the county of St. Louis and State 'of Missouri, have invented certain new and useful Improvements in Burglar-Alarms and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use it, reference being had to the accompanying drawings, which form part of this specification.

Myinvention relates to an improvement in burglar-alarms; and it consists in a screw for screwing into the wood-workof the windowshutter or door-jamb, and to whichis secured an elongated metallic head, provided with nipples at each end to receive gun caps. Slipped up over this screw, so as to cover the inner and outer sides and ends of the head, is a metallic case that bears against the caps, so that they will be exploded by pressure, and at the same time keep in the flash of the cap, to prevent the curtains from catching on lire. This device is to be used both as a burglaralarm and as door-fastener.

Figure 1 is a plan view of my invention.

' Fig. 2 is a horizontal section of the same.

a represents a powerful screw, upon the outer end of which is cast an elongated metallic head, b, which head is provided on its inner side with a nipple or projection, 0, at

each end, to receive a gun-cap. This head 12 is made of such a form and length as to best adapt it for fastening a door or shutter, at the j for bearing against the cap, to cause its ex: i

plosion from pressure, and for keeping in the flash of the cap, so that it cannotinjure the wood-work or set fire to the curtains when used in a window.

In using my invention, the screw is screwed into the wood-work of the door or windowshutter until the head comes down over the door, as shown in Fig. 1, like a button, or so as to catch over the catch on the windowframe, tohold the shutter fast. Any one attempting to force open the door or shutter will cause a pressure on the cap that will make it explode, and thus alarm the inmates of the house, scare away the burglar, and give notice to the police.

In order to cause the caps to explode easily,

the fulminate of a match may be placed in them, so that a very slight pressure will set them 0E.

Having thus described my invention, I

claim- A 1. The combination of the screw 00 and head 12, provided with the nipples c, substantially as shown, whereby a burglar-alarm and doorfastener is formed, as described.

2. The combination of the screw to, head I), nipples 0, and easing d, whereby a combined burglar-alarm and door-fastener is formed, substantially as described.

In testimony that I claim the foregoing I have hereunto set my hand this 20th day of September, 1875. I I

W. S. WATKINS.

Witnesses:

F. A. LEHMANN,

J NO. W. IRWIN. 

